/* ----------------------------------------------------------------------
* Copyright (C) 2010-2014 ARM Limited. All rights reserved.
*
* $Date:        19. March 2015
* $Revision: 	V.1.4.5
*
* Project: 	    CMSIS DSP Library
* Title:	    arm_mat_scale_q31.c
*
* Description:	Multiplies a Q31 matrix by a scalar.
*
* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*   - Redistributions of source code must retain the above copyright
*     notice, this list of conditions and the following disclaimer.
*   - Redistributions in binary form must reproduce the above copyright
*     notice, this list of conditions and the following disclaimer in
*     the documentation and/or other materials provided with the
*     distribution.
*   - Neither the name of ARM LIMITED nor the names of its contributors
*     may be used to endorse or promote products derived from this
*     software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.  ------------------------------------------------ */

#include "arm_math.h"

/**
 * @ingroup groupMatrix
 */

/**
 * @addtogroup MatrixScale
 * @{
 */

/**
 * @brief Q31 matrix scaling.
 * @param[in]       *pSrc points to input matrix
 * @param[in]       scaleFract fractional portion of the scale factor
 * @param[in]       shift number of bits to shift the result by
 * @param[out]      *pDst points to output matrix structure
 * @return     		The function returns either
 * <code>ARM_MATH_SIZE_MISMATCH</code> or <code>ARM_MATH_SUCCESS</code> based on the outcome of size checking.
 *
 * @details
 * <b>Scaling and Overflow Behavior:</b>
 * \par
 * The input data <code>*pSrc</code> and <code>scaleFract</code> are in 1.31 format.
 * These are multiplied to yield a 2.62 intermediate result and this is shifted with saturation to 1.31 format.
 */

arm_status arm_mat_scale_q31(
    const arm_matrix_instance_q31 *pSrc,
    q31_t scaleFract,
    int32_t shift,
    arm_matrix_instance_q31 *pDst)
{
    q31_t *pIn = pSrc->pData;                      /* input data matrix pointer */
    q31_t *pOut = pDst->pData;                     /* output data matrix pointer */
    uint32_t numSamples;                           /* total number of elements in the matrix */
    int32_t totShift = shift + 1;                  /* shift to apply after scaling */
    uint32_t blkCnt;                               /* loop counters  */
    arm_status status;                             /* status of matrix scaling      */
    q31_t in1, in2, out1;                          /* temporary variabels */

#ifndef ARM_MATH_CM0_FAMILY

    q31_t in3, in4, out2, out3, out4;              /* temporary variables */

#endif //      #ifndef ARM_MAT_CM0

#ifdef ARM_MATH_MATRIX_CHECK
    /* Check for matrix mismatch  */
    if((pSrc->numRows != pDst->numRows) || (pSrc->numCols != pDst->numCols))
    {
        /* Set status as ARM_MATH_SIZE_MISMATCH */
        status = ARM_MATH_SIZE_MISMATCH;
    }
    else
#endif //    #ifdef ARM_MATH_MATRIX_CHECK
    {
        /* Total number of samples in the input matrix */
        numSamples = (uint32_t) pSrc->numRows * pSrc->numCols;

#ifndef ARM_MATH_CM0_FAMILY

        /* Run the below code for Cortex-M4 and Cortex-M3 */

        /* Loop Unrolling */
        blkCnt = numSamples >> 2u;

        /* First part of the processing with loop unrolling.  Compute 4 outputs at a time.
         ** a second loop below computes the remaining 1 to 3 samples. */
        while(blkCnt > 0u)
        {
            /* C(m,n) = A(m,n) * k */
            /* Read values from input */
            in1 = *pIn;
            in2 = *(pIn + 1);
            in3 = *(pIn + 2);
            in4 = *(pIn + 3);

            /* multiply input with scaler value */
            in1 = ((q63_t) in1 * scaleFract) >> 32;
            in2 = ((q63_t) in2 * scaleFract) >> 32;
            in3 = ((q63_t) in3 * scaleFract) >> 32;
            in4 = ((q63_t) in4 * scaleFract) >> 32;

            /* apply shifting */
            out1 = in1 << totShift;
            out2 = in2 << totShift;

            /* saturate the results. */
            if(in1 != (out1 >> totShift))
                out1 = 0x7FFFFFFF ^ (in1 >> 31);

            if(in2 != (out2 >> totShift))
                out2 = 0x7FFFFFFF ^ (in2 >> 31);

            out3 = in3 << totShift;
            out4 = in4 << totShift;

            *pOut = out1;
            *(pOut + 1) = out2;

            if(in3 != (out3 >> totShift))
                out3 = 0x7FFFFFFF ^ (in3 >> 31);

            if(in4 != (out4 >> totShift))
                out4 = 0x7FFFFFFF ^ (in4 >> 31);


            *(pOut + 2) = out3;
            *(pOut + 3) = out4;

            /* update pointers to process next sampels */
            pIn += 4u;
            pOut += 4u;


            /* Decrement the numSamples loop counter */
            blkCnt--;
        }

        /* If the numSamples is not a multiple of 4, compute any remaining output samples here.
         ** No loop unrolling is used. */
        blkCnt = numSamples % 0x4u;

#else

        /* Run the below code for Cortex-M0 */

        /* Initialize blkCnt with number of samples */
        blkCnt = numSamples;

#endif /* #ifndef ARM_MATH_CM0_FAMILY */

        while(blkCnt > 0u)
        {
            /* C(m,n) = A(m,n) * k */
            /* Scale, saturate and then store the results in the destination buffer. */
            in1 = *pIn++;

            in2 = ((q63_t) in1 * scaleFract) >> 32;

            out1 = in2 << totShift;

            if(in2 != (out1 >> totShift))
                out1 = 0x7FFFFFFF ^ (in2 >> 31);

            *pOut++ = out1;

            /* Decrement the numSamples loop counter */
            blkCnt--;
        }

        /* Set status as ARM_MATH_SUCCESS */
        status = ARM_MATH_SUCCESS;
    }

    /* Return to application */
    return (status);
}

/**
 * @} end of MatrixScale group
 */
